#22. Mocked Date support.

source/JavascriptTimeAgo.js

@@ -349,7 +349,7 @@ JavascriptTimeAgo.locale = JavascriptTimeAgo.addLocale
 // Normalizes `.format()` `time` argument.
 function getDateAndTimeBeingFormatted(input)
 {
-	if (input.constructor === Date)
+	if (input.constructor === Date || isMockedDate(input))
 	{
 		return {
 			date : input,
@@ -372,6 +372,12 @@ function getDateAndTimeBeingFormatted(input)
 	throw new Error(`Unsupported relative time formatter input: ${typeof input}, ${input}`)
 }
 
+// During testing via some testing libraries `Date`s aren't actually `Date`s.
+// https://github.com/catamphetamine/javascript-time-ago/issues/22
+function isMockedDate(object) {
+	return typeof object === 'object' && typeof object.getTime === 'function'
+}
+
 // Get available time interval measurement units.
 function getTimeIntervalMeasurementUnits(localeData, restrictedSetOfUnits)
 {

source/JavascriptTimeAgo.test.js

@@ -64,6 +64,13 @@ describe(`time ago`, () =>
 		timeAgo.format(new Date()).should.equal('just now')
 	})
 
+	it(`should accept mocked Dates when testing`, () =>
+	{
+		const timeAgo = new JavascriptTimeAgo('en')
+		const mockedDate = { getTime: () => Date.now() }
+		timeAgo.format(mockedDate).should.equal('just now')
+	})
+
 	it(`should not accept anything but Dates and timestamps`, () =>
 	{
 		const timeAgo = new JavascriptTimeAgo('en')